Mayor Bloomberg went after Bronx DA Robert Johnson again today, saying he’s “dead wrong” not to prosecute some trespassers busted in housing projects.

“Do you want lower crime or don’t you?” the mayor asked. “I think most people who live in public housing want lower crime. They don’t want to look over their shoulders. They have a right to live safely and we’re going to provide that right. You don’t do that by making the cops’ job more difficult.”

It was the second day in a row that Bloomberg criticized Johnson, who has adopted a policy of not prosecuting trespassing violations issued during stop-and-frisk busts unless police officers come in for interviews to back up their documentation.

Bloomberg went out of his way to limit his remarks to the stop-and-frisk issue and not to denounce Johnson’s entire tenure as DA, even though he has the worst conviction rate of any DA.

“Look, I don’t need to have a fight with the Bronx DA,” the mayor. “I happen to like Bob. He does a lot of good work. I just think he’s dead wrong on this.”

Bloomberg conceded there’s not much he can do to influence the DA’s thinking other than through public persuasion.

“A lot of this, I believe, is up to the district attorney,” the mayor said. “District attorneys are elected. District attorneys read newspapers. District attorneys are human beings…”

Johnson, who was first elected in 1989, didn’t even have a challenger when he ran for re-election last year.